To those of our readers who may not be familiar with this subject, we would however take the liberty to remark, that porcelain clays generally arise from the decomposition of granite, and particularly of that kind which is denominated graphic granite, and which abounds with feldspar. It is, therefore, in the primitive countries that we are chiefly to expect them--such as New-England, and part of the high country of the middle and southern states. It should be observed, that if a clay, otherwise apparently good, burns red, it contains iron, and is unfit for porcelain; although it may serve well enough for more common and coarse earthen ware. ART. VIII. _Native Sulphur from Java._ Through the kindness of Mr. I. Huntington, recently returned from Java, we have received from that Island some fine specimens of native sulphur. They are very pure, of an orange yellow, slightly shaded with white, and occasionally with red; some of the cavities are lined with delicate crystals. What gives them particular interest is, that they are believed to be from that "large, and now nearly extinct, volcano, about sixty miles from the town of Batavia, at the bottom of which (of the crater) lie large quantities of native sulphur, even many hundred tons." It is in the crater of this volcano that the famous lake of sulphuric acid exists, and from which it flows down the mountain, and through the country below, a river of the same acid. (See Tilloch's Phil. Mag. Vol. XLII. p. 182.) It is a most curious phenomenon, and we believe entirely without a parallel. Another river, called the White River, unites with this some miles below its origin: this river, which is so called from the turbidness of its waters, its salutary to men and animals; fishes live in it, and vegetation is nourished by its waters; but after the junction it becomes clear; the acid dissolving the earthy particles which discoloured it, and it now becomes fatal to living beings: kills the fish, destroys the vegetation, and corrodes the stones in its channel. This remarkable river flows from Mount Idienne, in the province of Bagnia Vangni, in the eastern part of Java. ART. IX. _Productions of Wier's Cave, in Virginia._ We are indebted to the Reverend Elias Cornelius, and to Mr. John H. Kain, for a collection of the calcareous incrustations of Wier's Cave, in Virginia. The stalactites, and stalagmites, and various incrustations, are of uncommon size and beauty. Some of the stalactites have a delicate whiteness, and a brilliancy arising from their crystallized structure, which, with the regularity of their forms, give them a fair title to rank with those of the famous caverns in the Peak of Derbyshire, in the island of Antiparos, &c. In these stalactites, the structure is most remarkably distinct, both in the fibrous and concentric lamellar form. In this collection were observed many forms of the crystallized hard carbonates of lime, of Count Bournon.